Titanium dioxide nanocrystalline

Kay A (1996) Low cost photovoltaic modules based on dye sensitized nanocrystalline titanium dioxide and carbon powder. Solar Energy Mater Solar Cells 44 99-117 Wang X, Zhi L, Muellen K (2008) Transparent, conductive graphene electrodes for dye-sensitized solar cells. Nano Lett 8 323-327... 

The photoelectrochemical production of chlorine at nanocrystalline titanium dioxide thin film electrodes exposed to U V light has been reported [96]. In this process, the energy from photons substantially reduces the overpotential required for the chlorine evolution process and therefore less harsh conditions are required. Metal doping of the Ti02 photoelectrocatalyst was explored but found to be not beneficial for this process. In future, this kind of process could be of practical value, in particular, for water treatment and disinfection applications requiring low levels of chlorine. 

The nanocrystalline solids are metal oxides, especially titanium dioxide [54-58], Various dyes are used. Transition metal complexes such as (65) and (66) have broad absorption bands and allow the harvesting of a large fraction of sunlight [54,58], Fluorescent dyes are also used, such as Eosin-Y (67) [57], Dye-sensitized nanocrystalline solar cells are now giving efficiencies in excess of 10% [54,58], compared to just 1 % ten years ago [3],... 

Titanium Dioxide Particles Nanocrystalline Materials Battery Electrode Materials Contract Research... 

Turner, G.M., M.C. Beard, and C.A. Schmuttenmaer. 2002. Carrier localization and cooling in dye-sensitized nanocrystalline titanium dioxide. J. Phys. Chem. B 106 11716-11719. 

It should be noted that all above-mentioned results have been obtained using polycrystalline titanium dioxide (anatase, rutile) [49, 51] on the whole, the same regularities are observed during the control experiments with the monocrystalline rutile. When going from poly- to nanocrystalline Ti02 obtained by zol-gel method, the EER spectrum of the oxide substantially changes [53]. 

XRD analysis of the xerogels obtained by drying pure titanium dioxide sol at 70°C showed the presence of the nanocrystalline anatase phase [109]. Thermal treatment of this xerogel resulted in the growth of anatase crystallites up to 400°C. The anatase-to-rutile transformation began to occur at 450-500°C. This process was practically completed at 700°C, and only rutile phase existed at rcaic > 700°C. This feature of Ti02 xerogels is typical and well known (see, for example, [109]). Thus, it can be concluded that anatase-rutile transition temperature of nanosized particles is considerably lower than that of the... 

Macyk W, Stochel G, Szacilowski K. Photosensitization and photocurrent switching effect in nanocrystalline titanium dioxide functionalized with iron(II) complexes A comparative study. Chem Eur J 2007 13 5676-87. 

Szacilowski K, Macyk W, Hebda M, Stochel G. Redox-controlled photosensitization of nanocrystalline titanium dioxide. ChemPhysChem 2006 7 2384-91. 

Therefore inorganic sunscreens commonly used in cosmetic industry should be carefully tested for their photoactivity and phototoxicity. Sunscreens based on titanium and zinc oxides should contain additional antioxidants, eg a-tocopherol or j5-carotene. Even more efficient protection against unwanted ROSs can be achieved by a smart titanium dioxide modification that would block its photocatalytic activity. Recently Lee et al. described a hydrophobic multicomponent polymer coating for nanocrystalline Ti02 containing natural antioxidants extracted from grape seeds... 

Natarajan, C. and Nogami, G. (1996). Cathodic electrodeposition of nanocrystalline titanium dioxide thin films. J. Electrochem. Soc. 143(5), 1547-1550. 

Ellington RJ, Asbury JB, Ferrene S, Ghosh HN, Sprague JR, Lian T, Nozik AJ. Dynamics of electron injection in nanocrystalline titanium dioxide films sensitized with [Ru(4,4,-dicarboxy-2,2 -bipyridine)2(NCS)2] by infrared transient absorption. J Phys Chem B 1998 102 6455-6458. 

The fastest kinetic phase of electron injection in c/j-[Ru (dcbpy)2(NCS)2]-sensitized nanocrystalline titanium dioxide films apparently takes place in the femtosecond regime. Besides, the vibrational relaxation of the dye excited state is expected to occur typically within 0.4-1 ps k 10 s ) [57, 58]. Observed injec-... 

Photovoltaic cells based on the sensitization of mesoporous titanium dioxide by Ru(II) complex dyes in conjunction with the I.3 /U redox couple as a mediator have proved very efficient at exploiting this principle. In such systems, the ionic mediator travels back and forth by diffusion from the working electrode to the counterelectrode, to shuttle to the sensitizer the electrons that have gone through the electrical circuit [18, 21, 84]. Recently, solid-state devices have been described where the liquid electrolyte present in the pores of the nanocrystalline oxide film is replaced by a large-bandgap p-type semiconductor acting as a hole-transport medium [85 88]. 

Tachibana Y., Moser J. E., Gratzel M., King D. R. and Durrant J. R. (1996), Subpicosecond interfacial charge separation in dye-sensitized nanocrystalline titanium dioxide films , J. Phys. Chem. 100, 20056-20062. 

Lyon L. A. and Hupp J. T. (1999), Energetics of the nanocrystalline titanium dioxide aqueous solution interface approximate conduction band edge variations between Ho = -10 and H = +26 , /. Phys. Chem. B 103, 4623-4628. 

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